# ##### BEGIN GPL LICENSE BLOCK #####
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# ##### END GPL LICENSE BLOCK #####


"""
See documentation for usage
https://github.com/CGCookie/blender-addon-updater

"""

import errno
import fnmatch
import json
import os
import shutil
import ssl
import threading
import urllib
import urllib.request
import zipfile
from datetime import datetime, timedelta

import addon_utils

# blender imports, used in limited cases
import bpy

# -----------------------------------------------------------------------------
# Define error messages/notices & hard coded globals
# -----------------------------------------------------------------------------

# currently not used
DEFAULT_TIMEOUT = 10
DEFAULT_PER_PAGE = 30


# -----------------------------------------------------------------------------
# The main class
# -----------------------------------------------------------------------------


class SingletonUpdater(object):
    """
    This is the singleton class to reference a copy from,
    it is the shared module level class
    """

    def __init__(self):
        self._engine = GithubEngine()
        self._user = None
        self._repo = None
        self._website = None
        self._current_version = None
        self._subfolder_path = None
        self._tags = []
        self._tag_latest = None
        self._tag_names = []
        self._latest_release = None
        self._use_releases = False
        self._include_branches = False
        self._include_branch_list = ["master"]
        self._include_branch_autocheck = False
        self._manual_only = False
        self._version_min_update = None
        self._version_max_update = None

        # by default, backup current addon if new is being loaded
        self._backup_current = True
        self._backup_ignore_patterns = None

        # set patterns for what files to overwrite on update
        self._overwrite_patterns = ["*.py", "*.pyc"]
        self._remove_pre_update_patterns = []

        # by default, don't auto enable/disable the addon on update
        # as it is slightly less stable/won't always fully reload module
        self._auto_reload_post_update = False

        # settings relating to frequency and whether to enable auto background check
        self._check_interval_enable = False
        self._check_interval_months = 0
        self._check_interval_days = 7
        self._check_interval_hours = 0
        self._check_interval_minutes = 0

        # runtime variables, initial conditions
        self._verbose = False
        self._fake_install = False
        self._async_checking = False  # only true when async daemon started
        self._update_ready = None
        self._update_link = None
        self._update_version = None
        self._source_zip = None
        self._check_thread = None
        self._select_link = None
        self.skip_tag = None

        # get from module data
        self._addon = __package__.lower()
        self._addon_package = __package__  # must not change
        self._updater_path = os.path.join(
            os.path.dirname(__file__), self._addon + "_updater"
        )
        self._addon_root = os.path.dirname(__file__)
        self._json = {}
        self._error = None
        self._error_msg = None
        self._prefiltered_tag_count = 0

        # UI code only, i.e., not used within this module but still useful
        # properties to have

        # to verify a valid import, in place of placeholder import
        self.showpopups = True  # used in UI to show or not show update popups
        self.invalidupdater = False

        # pre-assign basic select-link function
        def select_link_function(tag):
            return tag["zipball_url"]

        self._select_link = select_link_function

    # -------------------------------------------------------------------------
    # Getters and setters
    # -------------------------------------------------------------------------

    @property
    def addon(self):
        return self._addon

    @addon.setter
    def addon(self, value):
        self._addon = str(value)

    @property
    def api_url(self):
        return self._engine.api_url

    @api_url.setter
    def api_url(self, value):
        if not self.check_is_url(value):
            raise ValueError("Not a valid URL: " + value)
        self._engine.api_url = value

    @property
    def async_checking(self):
        return self._async_checking

    @property
    def auto_reload_post_update(self):
        return self._auto_reload_post_update

    @auto_reload_post_update.setter
    def auto_reload_post_update(self, value):
        try:
            self._auto_reload_post_update = bool(value)
        except ValueError:
            raise ValueError("Must be a boolean value")

    @property
    def backup_current(self):
        return self._backup_current

    @backup_current.setter
    def backup_current(self, value):
        if value is None:
            self._backup_current = False
            return
        else:
            self._backup_current = value

    @property
    def backup_ignore_patterns(self):
        return self._backup_ignore_patterns

    @backup_ignore_patterns.setter
    def backup_ignore_patterns(self, value):
        if value is None:
            self._backup_ignore_patterns = None
            return
        elif not isinstance(value, list):
            raise ValueError("Backup pattern must be in list format")
        else:
            self._backup_ignore_patterns = value

    @property
    def check_interval(self):
        return (
            self._check_interval_enable,
            self._check_interval_months,
            self._check_interval_days,
            self._check_interval_hours,
            self._check_interval_minutes,
        )

    @property
    def current_version(self):
        return self._current_version

    @current_version.setter
    def current_version(self, tuple_values):
        if tuple_values is None:
            self._current_version = None
            return
        elif type(tuple_values) is not tuple:
            try:
                tuple(tuple_values)
            except ValueError:
                raise ValueError(
                    "Not a tuple! current_version must be a tuple of integers"
                )
        for i in tuple_values:
            if type(i) is not int:
                raise ValueError(
                    "Not an integer! current_version must be a tuple of integers"
                )
        self._current_version = tuple(tuple_values)

    @property
    def engine(self):
        return self._engine.name

    @engine.setter
    def engine(self, value):
        if value.lower() == "github":
            self._engine = GithubEngine()
        elif value.lower() == "gitlab":
            self._engine = GitlabEngine()
        elif value.lower() == "bitbucket":
            self._engine = BitbucketEngine()
        else:
            raise ValueError("Invalid engine selection")

    @property
    def error(self):
        return self._error

    @property
    def error_msg(self):
        return self._error_msg

    @property
    def fake_install(self):
        return self._fake_install

    @fake_install.setter
    def fake_install(self, value):
        if not isinstance(value, bool):
            raise ValueError("fake_install must be a boolean value")
        self._fake_install = bool(value)

    # not currently used
    @property
    def include_branch_autocheck(self):
        return self._include_branch_autocheck

    @include_branch_autocheck.setter
    def include_branch_autocheck(self, value):
        try:
            self._include_branch_autocheck = bool(value)
        except ValueError:
            raise ValueError("include_branch_autocheck must be a boolean value")

    @property
    def include_branch_list(self):
        return self._include_branch_list

    @include_branch_list.setter
    def include_branch_list(self, value):
        try:
            if value is None:
                self._include_branch_list = ["master"]
            elif not isinstance(value, list) or value == []:
                raise ValueError(
                    "include_branch_list should be a list of valid branches"
                )
            else:
                self._include_branch_list = value
        except ValueError:
            raise ValueError("include_branch_list should be a list of valid branches")

    @property
    def include_branches(self):
        return self._include_branches

    @include_branches.setter
    def include_branches(self, value):
        try:
            self._include_branches = bool(value)
        except ValueError:
            raise ValueError("include_branches must be a boolean value")

    @property
    def json(self):
        if self._json == {}:
            self.set_updater_json()
        return self._json

    @property
    def latest_release(self):
        if self._latest_release is None:
            return None
        return self._latest_release

    @property
    def manual_only(self):
        return self._manual_only

    @manual_only.setter
    def manual_only(self, value):
        try:
            self._manual_only = bool(value)
        except ValueError:
            raise ValueError("manual_only must be a boolean value")

    @property
    def overwrite_patterns(self):
        return self._overwrite_patterns

    @overwrite_patterns.setter
    def overwrite_patterns(self, value):
        if value is None:
            self._overwrite_patterns = ["*.py", "*.pyc"]
        elif not isinstance(value, list):
            raise ValueError("overwrite_patterns needs to be in a list format")
        else:
            self._overwrite_patterns = value

    @property
    def private_token(self):
        return self._engine.token

    @private_token.setter
    def private_token(self, value):
        if value is None:
            self._engine.token = None
        else:
            self._engine.token = str(value)

    @property
    def remove_pre_update_patterns(self):
        return self._remove_pre_update_patterns

    @remove_pre_update_patterns.setter
    def remove_pre_update_patterns(self, value):
        if value is None:
            self._remove_pre_update_patterns = []
        elif not isinstance(value, list):
            raise ValueError("remove_pre_update_patterns needs to be in a list format")
        else:
            self._remove_pre_update_patterns = value

    @property
    def repo(self):
        return self._repo

    @repo.setter
    def repo(self, value):
        try:
            self._repo = str(value)
        except ValueError:
            raise ValueError("User must be a string")

    @property
    def select_link(self):
        return self._select_link

    @select_link.setter
    def select_link(self, value):
        # ensure it is a function assignment, with signature:
        # input self, tag; returns link name
        if not hasattr(value, "__call__"):
            raise ValueError("select_link must be a function")
        self._select_link = value

    @property
    def stage_path(self):
        return self._updater_path

    @stage_path.setter
    def stage_path(self, value):
        if value is None:
            if self._verbose:
                print("Aborting assigning stage_path, it's null")
            return
        elif value is not None and not os.path.exists(value):
            try:
                os.makedirs(value)
            except OSError:
                if self._verbose:
                    print("Error trying to staging path")
                return
        self._updater_path = value

    @property
    def subfolder_path(self):
        return self._subfolder_path

    @subfolder_path.setter
    def subfolder_path(self, value):
        self._subfolder_path = value

    @property
    def tags(self):
        if self._tags == []:
            return []
        tag_names = []
        for tag in self._tags:
            tag_names.append(tag["name"])
        return tag_names

    @property
    def tag_latest(self):
        if self._tag_latest is None:
            return None
        return self._tag_latest["name"]

    @property
    def update_link(self):
        return self._update_link

    @property
    def update_ready(self):
        return self._update_ready

    @property
    def update_version(self):
        return self._update_version

    @property
    def use_releases(self):
        return self._use_releases

    @use_releases.setter
    def use_releases(self, value):
        try:
            self._use_releases = bool(value)
        except ValueError:
            raise ValueError("use_releases must be a boolean value")

    @property
    def user(self):
        return self._user

    @user.setter
    def user(self, value):
        try:
            self._user = str(value)
        except ValueError:
            raise ValueError("User must be a string value")

    @property
    def verbose(self):
        return self._verbose

    @verbose.setter
    def verbose(self, value):
        try:
            self._verbose = bool(value)
            if self._verbose is True:
                print(self._addon + " updater verbose is enabled")
        except ValueError:
            raise ValueError("Verbose must be a boolean value")

    @property
    def version_max_update(self):
        return self._version_max_update

    @version_max_update.setter
    def version_max_update(self, value):
        if value is None:
            self._version_max_update = None
            return
        if not isinstance(value, tuple):
            raise ValueError("Version maximum must be a tuple")
        for subvalue in value:
            if type(subvalue) is not int:
                raise ValueError("Version elements must be integers")
        self._version_max_update = value

    @property
    def version_min_update(self):
        return self._version_min_update

    @version_min_update.setter
    def version_min_update(self, value):
        if value is None:
            self._version_min_update = None
            return
        if not isinstance(value, tuple):
            raise ValueError("Version minimum must be a tuple")
        for subvalue in value:
            if type(subvalue) is not int:
                raise ValueError("Version elements must be integers")
        self._version_min_update = value

    @property
    def website(self):
        return self._website

    @website.setter
    def website(self, value):
        if self.check_is_url(value) is False:
            raise ValueError("Not a valid URL: " + value)
        self._website = value

    # -------------------------------------------------------------------------
    # Parameter validation related functions
    # -------------------------------------------------------------------------

    @staticmethod
    def check_is_url(url):
        if not ("http://" in url or "https://" in url):
            return False
        if "." not in url:
            return False
        return True

    def get_tag_names(self):
        tag_names = []
        self.get_tags()
        for tag in self._tags:
            tag_names.append(tag["name"])
        return tag_names

    def set_check_interval(self, enable=False, months=0, days=14, hours=0, minutes=0):
        # enabled = False, default initially will not check against frequency
        # if enabled, default is then 2 weeks

        if type(enable) is not bool:
            raise ValueError("Enable must be a boolean value")
        if type(months) is not int:
            raise ValueError("Months must be an integer value")
        if type(days) is not int:
            raise ValueError("Days must be an integer value")
        if type(hours) is not int:
            raise ValueError("Hours must be an integer value")
        if type(minutes) is not int:
            raise ValueError("Minutes must be an integer value")

        if enable is False:
            self._check_interval_enable = False
        else:
            self._check_interval_enable = True

        self._check_interval_months = months
        self._check_interval_days = days
        self._check_interval_hours = hours
        self._check_interval_minutes = minutes

    # declare how the class gets printed

    def __repr__(self):
        return "<Module updater from {a}>".format(a=__file__)

    def __str__(self):
        return "Updater, with user: {a}, repository: {b}, url: {c}".format(
            a=self._user, b=self._repo, c=self.form_repo_url()
        )

    # -------------------------------------------------------------------------
    # API-related functions
    # -------------------------------------------------------------------------

    def form_repo_url(self):
        return self._engine.form_repo_url(self)

    def form_tags_url(self):
        return self._engine.form_tags_url(self)

    def form_branch_url(self, branch):
        return self._engine.form_branch_url(branch, self)

    def get_tags(self):
        request = self.form_tags_url()
        if self._verbose:
            print("Getting tags from server")

        # get all tags, internet call
        all_tags = self._engine.parse_tags(self.get_api(request), self)
        if all_tags is not None:
            self._prefiltered_tag_count = len(all_tags)
        else:
            self._prefiltered_tag_count = 0
            all_tags = []

        # pre-process to skip tags
        if self.skip_tag is not None:
            self._tags = [tg for tg in all_tags if self.skip_tag(self, tg) is False]
        else:
            self._tags = all_tags

        # get additional branches too, if needed, and place in front
        # Does NO checking here whether branch is valid
        if self._include_branches is True:
            temp_branches = self._include_branch_list.copy()
            temp_branches.reverse()
            for branch in temp_branches:
                request = self.form_branch_url(branch)
                include = {"name": branch.title(), "zipball_url": request}
                self._tags = [include] + self._tags  # append to front

        if self._tags is None:
            # some error occurred
            self._tag_latest = None
            self._tags = []
            return
        elif self._prefiltered_tag_count == 0 and self._include_branches is False:
            self._tag_latest = None
            if self._error is None:
                self._error = "No releases found"
                self._error_msg = "No releases or tags found on this repository"
            if self._verbose:
                print("No releases or tags found on this repository")
        elif self._prefiltered_tag_count == 0 and self._include_branches is True:
            if not self._error:
                self._tag_latest = self._tags[0]
            if self._verbose:
                branch = self._include_branch_list[0]
                print("{} branch found, no releases".format(branch), self._tags[0])
        elif (
            (
                len(self._tags) - len(self._include_branch_list) == 0
                and self._include_branches is True
            )
            or (len(self._tags) == 0 and self._include_branches is False)
            and self._prefiltered_tag_count > 0
        ):
            self._tag_latest = None
            self._error = "No releases available"
            self._error_msg = "No versions found within compatible version range"
            if self._verbose:
                print("No versions found within compatible version range")
        else:
            if self._include_branches is False:
                self._tag_latest = self._tags[0]
                if self._verbose:
                    print("Most recent tag found:", self._tags[0]["name"])
            else:
                # don't return branch if in list
                n = len(self._include_branch_list)
                self._tag_latest = self._tags[n]  # guaranteed at least len()=n+1
                if self._verbose:
                    print("Most recent tag found:", self._tags[n]["name"])

    # all API calls to base url
    def get_raw(self, url):
        # print("Raw request:", url)
        request = urllib.request.Request(url)
        try:
            context = ssl._create_unverified_context()
        except AttributeError:
            # some blender packaged python versions don't have this, largely
            # useful for local network setups otherwise minimal impact
            context = None

        # setup private request headers if appropriate
        if self._engine.token is not None:
            if self._engine.name == "gitlab":
                request.add_header("PRIVATE-TOKEN", self._engine.token)
            else:
                if self._verbose:
                    print("Tokens not setup for engine yet")

        # run the request
        try:
            if context:
                result = urllib.request.urlopen(request, context=context)
            else:
                result = urllib.request.urlopen(request)
        except urllib.error.HTTPError as e:
            if str(e.code) == "403":
                self._error = "HTTP error (access denied)"
                self._error_msg = str(e.code) + " - server error response"
                print(self._error, self._error_msg)
            else:
                self._error = "HTTP error"
                self._error_msg = str(e.code)
                print(self._error, self._error_msg)
            self._update_ready = None
        except urllib.error.URLError as e:
            reason = str(e.reason)
            if "TLSV1_ALERT" in reason or "SSL" in reason.upper():
                self._error = "Connection rejected, download manually"
                self._error_msg = reason
                print(self._error, self._error_msg)
            else:
                self._error = "URL error, check internet connection"
                self._error_msg = reason
                print(self._error, self._error_msg)
            self._update_ready = None
            return None
        else:
            result_string = result.read()
            result.close()
            return result_string.decode()

    # result of all api calls, decoded into json format
    def get_api(self, url):
        # return the json version
        get = self.get_raw(url)
        if get is not None:
            try:
                return json.JSONDecoder().decode(get)
            except json.JSONDecodeError as e:
                self._error = "API response has invalid JSON format"
                self._error_msg = str(e.msg)
                self._update_ready = None
                print(self._error, self._error_msg)
                return None
        else:
            return None

    # create a working directory and download the new files
    def stage_repository(self, url):
        local = os.path.join(self._updater_path, "update_staging")
        error = None

        # make/clear the staging folder
        # ensure the folder is always "clean"
        if self._verbose:
            print("Preparing staging folder for download:\n", local)
        if os.path.isdir(local) is True:
            try:
                shutil.rmtree(local)
                os.makedirs(local)
            except OSError:
                error = "failed to remove existing staging directory"
        else:
            try:
                os.makedirs(local)
            except OSError:
                error = "failed to create staging directory"

        if error is not None:
            if self._verbose:
                print("Error: Aborting update, " + error)
            self._error = "Update aborted, staging path error"
            self._error_msg = "Error: {}".format(error)
            return False

        if self._backup_current is True:
            self.create_backup()
        if self._verbose:
            print("Now retrieving the new source zip")

        self._source_zip = os.path.join(local, "source.zip")

        if self._verbose:
            print("Starting download update zip")
        try:
            request = urllib.request.Request(url)
            context = ssl._create_unverified_context()

            # setup private token if appropriate
            if self._engine.token is not None:
                if self._engine.name == "gitlab":
                    request.add_header("PRIVATE-TOKEN", self._engine.token)
                else:
                    if self._verbose:
                        print("Tokens not setup for selected engine yet")
            self.urlretrieve(
                urllib.request.urlopen(request, context=context), self._source_zip
            )
            # add additional checks on file size being non-zero
            if self._verbose:
                print("Successfully downloaded update zip")
            return True
        except Exception as e:
            self._error = "Error retrieving download, bad link?"
            self._error_msg = "Error: {}".format(e)
            if self._verbose:
                print("Error retrieving download, bad link?")
                print("Error: {}".format(e))
            return False

    def create_backup(self):
        if self._verbose:
            print("Backing up current addon folder")
        local = os.path.join(self._updater_path, "backup")
        tempdest = os.path.join(
            self._addon_root, os.pardir, self._addon + "_updater_backup_temp"
        )

        if self._verbose:
            print("Backup destination path: ", local)

        if os.path.isdir(local):
            try:
                shutil.rmtree(local)
            except OSError:
                if self._verbose:
                    print("Failed to removed previous backup folder, contininuing")

        # remove the temp folder; shouldn't exist but could if previously interrupted
        if os.path.isdir(tempdest):
            try:
                shutil.rmtree(tempdest)
            except OSError:
                if self._verbose:
                    print("Failed to remove existing temp folder, contininuing")
        # make the full addon copy, which temporarily places outside the addon folder
        if self._backup_ignore_patterns is not None:
            shutil.copytree(
                self._addon_root,
                tempdest,
                ignore=shutil.ignore_patterns(*self._backup_ignore_patterns),
            )
        else:
            shutil.copytree(self._addon_root, tempdest)
        shutil.move(tempdest, local)

        # save the date for future ref
        now = datetime.now()
        self._json["backup_date"] = "{m}-{d}-{yr}".format(
            m=now.strftime("%B"), d=now.day, yr=now.year
        )
        self.save_updater_json()

    def restore_backup(self):
        if self._verbose:
            print("Restoring backup")
        if self._verbose:
            print("Backing up current addon folder")
        backuploc = os.path.join(self._updater_path, "backup")
        tempdest = os.path.join(
            self._addon_root, os.pardir, self._addon + "_updater_backup_temp"
        )
        tempdest = os.path.abspath(tempdest)

        # make the copy
        shutil.move(backuploc, tempdest)
        shutil.rmtree(self._addon_root)
        os.rename(tempdest, self._addon_root)

        self._json["backup_date"] = ""
        self._json["just_restored"] = True
        self._json["just_updated"] = True
        self.save_updater_json()

        self.reload_addon()

    def unpack_staged_zip(self, clean=False):
        """Unzip the downloaded file, and validate contents"""
        if not os.path.isfile(self._source_zip):
            if self._verbose:
                print("Error, update zip not found")
            self._error = "Install failed"
            self._error_msg = "Downloaded zip not found"
            return -1

        # clear the existing source folder in case previous files remain
        outdir = os.path.join(self._updater_path, "source")
        try:
            shutil.rmtree(outdir)
            if self._verbose:
                print("Source folder cleared and recreated")
        except OSError:
            pass

        # Create parent directories if needed, would not be relevant unless
        # installing addon into another location or via an addon manager
        try:
            os.mkdir(outdir)
        except Exception as err:
            print("Error occurred while making extract dir:")
            print(str(err))
            self._error = "Install failed"
            self._error_msg = "Failed to make extract directory"
            return -1

        if not os.path.isdir(outdir):
            print("Failed to create source directory")
            self._error = "Install failed"
            self._error_msg = "Failed to create extract directory"
            return -1

        if self._verbose:
            print("Begin extracting source from zip:", self._source_zip)
        zfile = zipfile.ZipFile(self._source_zip, "r")

        if not zfile:
            if self._verbose:
                print("Resulting file is not a zip, cannot extract")
            self._error = "Install failed"
            self._error_msg = "Resulting file is not a zip, cannot extract"
            return -1

        # Now extract directly from the first subfolder (not root)
        # this avoids adding the first subfolder to the path length,
        # which can be too long if the download has the SHA in the name
        zsep = "/"  # os.sep  # might just always be / even on windows
        for name in zfile.namelist():
            if zsep not in name:
                continue
            top_folder = name[: name.index(zsep) + 1]
            if name == top_folder + zsep:
                continue  # skip top level folder
            subpath = name[name.index(zsep) + 1 :]
            if name.endswith(zsep):
                try:
                    os.mkdir(os.path.join(outdir, subpath))
                    if self._verbose:
                        print("Extract - mkdir: ", os.path.join(outdir, subpath))
                except OSError as exc:
                    if exc.errno != errno.EEXIST:
                        self._error = "Install failed"
                        self._error_msg = "Could not create folder from zip"
                        return -1
            else:
                with open(os.path.join(outdir, subpath), "wb") as outfile:
                    data = zfile.read(name)
                    outfile.write(data)
                    if self._verbose:
                        print("Extract - create:", os.path.join(outdir, subpath))

        if self._verbose:
            print("Extracted source")

        unpath = os.path.join(self._updater_path, "source")
        if not os.path.isdir(unpath):
            self._error = "Install failed"
            self._error_msg = "Extracted path does not exist"
            print("Extracted path does not exist: ", unpath)
            return -1

        if self._subfolder_path:
            self._subfolder_path.replace("/", os.path.sep)
            self._subfolder_path.replace("\\", os.path.sep)

        # either directly in root of zip/one subfolder, or use specified path
        if os.path.isfile(os.path.join(unpath, "__init__.py")) is False:
            dirlist = os.listdir(unpath)
            if len(dirlist) > 0:
                if self._subfolder_path == "" or self._subfolder_path is None:
                    unpath = os.path.join(unpath, dirlist[0])
                else:
                    unpath = os.path.join(unpath, self._subfolder_path)

            # smarter check for additional sub folders for a single folder
            # containing __init__.py
            if os.path.isfile(os.path.join(unpath, "__init__.py")) is False:
                if self._verbose:
                    print("not a valid addon found")
                    print("Paths:")
                    print(dirlist)
                self._error = "Install failed"
                self._error_msg = "No __init__ file found in new source"
                return -1

        # merge code with running addon directory, using blender default behavior
        # plus any modifiers indicated by user (e.g. force remove/keep)
        self.deep_merge_directory(self._addon_root, unpath, clean)

        # Now save the json state
        #  Change to True, to trigger the handler on other side
        #  if allowing reloading within same blender instance
        self._json["just_updated"] = True
        self.save_updater_json()
        self.reload_addon()
        self._update_ready = False
        return 0

    def deep_merge_directory(self, base, merger, clean=False):
        """Merge folder 'merger' into folder 'base' without deleting existing"""
        if not os.path.exists(base):
            if self._verbose:
                print("Base path does not exist:", base)
            return -1
        elif not os.path.exists(merger):
            if self._verbose:
                print("Merger path does not exist")
            return -1

        # paths to be aware of and not overwrite/remove/etc
        staging_path = os.path.join(self._updater_path, "update_staging")

        # If clean installation is enabled, clear existing files ahead of time
        # note: will not delete the update.json, update folder, staging, or staging
        # but will delete all other folders/files in addon directory
        if clean:
            try:
                # implement clearing of all folders/files, except the
                # updater folder and updater json
                # Careful, this deletes entire subdirectories recursively...
                # make sure that base is not a high level shared folder, but
                # is dedicated just to the addon itself
                if self._verbose:
                    print("clean=True, clearing addon folder to fresh install state")

                # remove root files and folders (except update folder)
                files = [
                    f for f in os.listdir(base) if os.path.isfile(os.path.join(base, f))
                ]
                folders = [
                    f for f in os.listdir(base) if os.path.isdir(os.path.join(base, f))
                ]

                for f in files:
                    os.remove(os.path.join(base, f))
                    print("Clean removing file {}".format(os.path.join(base, f)))
                for f in folders:
                    if os.path.join(base, f) == self._updater_path:
                        continue
                    shutil.rmtree(os.path.join(base, f))
                    print(
                        "Clean removing folder and contents {}".format(
                            os.path.join(base, f)
                        )
                    )

            except Exception as err:
                error = "failed to create clean existing addon folder"
                print(error, str(err))

        # Walk through the base addon folder for rules on pre-removing
        # but avoid removing/altering backup and updater file
        for path, dirs, files in os.walk(base):
            # prune ie skip updater folder
            dirs[:] = [
                d for d in dirs if os.path.join(path, d) not in [self._updater_path]
            ]
            for file in files:
                for ptrn in self.remove_pre_update_patterns:
                    if fnmatch.filter([file], ptrn):
                        try:
                            fl = os.path.join(path, file)
                            os.remove(fl)
                            if self._verbose:
                                print("Pre-removed file " + file)
                        except OSError:
                            print("Failed to pre-remove " + file)

        # Walk through the temp addon sub folder for replacements
        # this implements the overwrite rules, which apply after
        # the above pre-removal rules. This also performs the
        # actual file copying/replacements
        for path, dirs, files in os.walk(merger):
            # verify this structure works to prune updater sub folder overwriting
            dirs[:] = [
                d for d in dirs if os.path.join(path, d) not in [self._updater_path]
            ]
            rel_path = os.path.relpath(path, merger)
            dest_path = os.path.join(base, rel_path)
            if not os.path.exists(dest_path):
                os.makedirs(dest_path)
            for file in files:
                # bring in additional logic around copying/replacing
                # Blender default: overwrite .py's, don't overwrite the rest
                dest_file = os.path.join(dest_path, file)
                src_file = os.path.join(path, file)

                # decide whether to replace if file already exists, and copy new over
                if os.path.isfile(dest_file):
                    # otherwise, check each file to see if matches an overwrite pattern
                    replaced = False
                    for ptrn in self._overwrite_patterns:
                        if fnmatch.filter([dest_file], ptrn):
                            replaced = True
                            break
                    if replaced:
                        os.remove(dest_file)
                        os.rename(src_file, dest_file)
                        if self._verbose:
                            print("Overwrote file " + os.path.basename(dest_file))
                    else:
                        if self._verbose:
                            print(
                                "Pattern not matched to "
                                + os.path.basename(dest_file)
                                + ", not overwritten"
                            )
                else:
                    # file did not previously exist, simply move it over
                    os.rename(src_file, dest_file)
                    if self._verbose:
                        print("New file " + os.path.basename(dest_file))

        # now remove the temp staging folder and downloaded zip
        try:
            shutil.rmtree(staging_path)
        except OSError:
            error = (
                "Error: Failed to remove existing staging directory, consider manually removing "
                + staging_path
            )
            if self._verbose:
                print(error)

    def reload_addon(self):
        # if post_update false, skip this function
        # else, unload/reload addon & trigger popup
        if self._auto_reload_post_update is False:
            print("Restart blender to reload addon and complete update")
            return

        if self._verbose:
            print("Reloading addon...")
        addon_utils.modules(refresh=True)
        bpy.utils.refresh_script_paths()

        # not allowed in restricted context, such as register module
        # toggle to refresh
        bpy.ops.wm.addon_disable(module=self._addon_package)
        bpy.ops.wm.addon_refresh()
        bpy.ops.wm.addon_enable(module=self._addon_package)

    # -------------------------------------------------------------------------
    # Other non-api functions and setups
    # -------------------------------------------------------------------------

    def clear_state(self):
        self._update_ready = None
        self._update_link = None
        self._update_version = None
        self._source_zip = None
        self._error = None
        self._error_msg = None

    # custom urlretrieve implementation
    def urlretrieve(self, urlfile, filepath):
        chunk = 1024 * 8
        f = open(filepath, "wb")
        while 1:
            data = urlfile.read(chunk)
            if not data:
                # print("done.")
                break
            f.write(data)
            # print("Read %s bytes"%len(data))
        f.close()

    def version_tuple_from_text(self, text):
        if text is None:
            return ()

        # should go through string and remove all non-integers,
        # and for any given break split into a different section
        segments = []
        tmp = ""
        for L in str(text):
            if L.isdigit() is False:
                if len(tmp) > 0:
                    segments.append(int(tmp))
                    tmp = ""
            else:
                tmp += L
        if len(tmp) > 0:
            segments.append(int(tmp))

        if len(segments) == 0:
            if self._verbose:
                print("No version strings found text: ", text)
            if self._include_branches is False:
                return ()
            else:
                return text
        return tuple(segments)

    # called for running check in a background thread
    def check_for_update_async(self, callback=None):
        if (
            self._json is not None
            and "update_ready" in self._json
            and self._json["version_text"] != {}
        ):
            if self._json["update_ready"] is True:
                self._update_ready = True
                self._update_link = self._json["version_text"]["link"]
                self._update_version = str(self._json["version_text"]["version"])
                # cached update
                callback(True)
                return

        # do the check
        if self._check_interval_enable is False:
            return
        elif self._async_checking is True:
            if self._verbose:
                print("Skipping async check, already started")
            return  # already running the bg thread
        elif self._update_ready is None:
            self.start_async_check_update(False, callback)

    def check_for_update_now(self, callback=None):
        self._error = None
        self._error_msg = None

        if self._verbose:
            print("Check update pressed, first getting current status")
        if self._async_checking is True:
            if self._verbose:
                print("Skipping async check, already started")
            return  # already running the bg thread
        elif self._update_ready is None:
            self.start_async_check_update(True, callback)
        else:
            self._update_ready = None
            self.start_async_check_update(True, callback)

    # this function is not async, will always return in sequential fashion
    # but should have a parent which calls it in another thread
    def check_for_update(self, now=False):
        if self._verbose:
            print("Checking for update function")

        # clear the errors if any
        self._error = None
        self._error_msg = None

        # avoid running again in, just return past result if found
        # but if force now check, then still do it
        if self._update_ready is not None and now is False:
            return self._update_ready, self._update_version, self._update_link

        if self._current_version is None:
            raise ValueError("current_version not yet defined")
        if self._repo is None:
            raise ValueError("repo not yet defined")
        if self._user is None:
            raise ValueError("username not yet defined")

        self.set_updater_json()  # self._json

        if now is False and self.past_interval_timestamp() is False:
            if self._verbose:
                print("Aborting check for updated, check interval not reached")
            return False, None, None

        # check if using tags or releases
        # note that if called the first time, this will pull tags from online
        if self._fake_install is True:
            if self._verbose:
                print("fake_install = True, setting fake version as ready")
            self._update_ready = True
            self._update_version = "(999,999,999)"
            self._update_link = "http://127.0.0.1"

            return self._update_ready, self._update_version, self._update_link

        # primary internet call
        self.get_tags()  # sets self._tags and self._tag_latest

        self._json["last_check"] = str(datetime.now())
        self.save_updater_json()

        # can be () or ('master') in addition to branches, and version tag
        new_version = self.version_tuple_from_text(self.tag_latest)

        if len(self._tags) == 0:
            self._update_ready = False
            self._update_version = None
            self._update_link = None
            return False, None, None
        if self._include_branches is False:
            link = self.select_link(self._tags[0])
        else:
            n = len(self._include_branch_list)
            if len(self._tags) == n:
                # effectively means no tags found on repo
                # so provide the first one as default
                link = self.select_link(self._tags[0])
            else:
                link = self.select_link(self._tags[n])

        if new_version == ():
            self._update_ready = False
            self._update_version = None
            self._update_link = None
            return False, None, None
        elif str(new_version).lower() in self._include_branch_list:
            # handle situation where master/whichever branch is included
            # however, this code effectively is not triggered now
            # as new_version will only be tag names, not branch names
            if self._include_branch_autocheck is False:
                # don't offer update as ready,
                # but set the link for the default
                # branch for installing
                self._update_ready = False
                self._update_version = new_version
                self._update_link = link
                self.save_updater_json()
                return True, new_version, link
            else:
                raise ValueError("include_branch_autocheck: NOT YET DEVELOPED")
                # bypass releases and look at timestamp of last update
                # from a branch compared to now, see if commit values
                # match or not.

        else:
            # situation where branches not included

            if new_version > self._current_version:
                self._update_ready = True
                self._update_version = new_version
                self._update_link = link
                self.save_updater_json()
                return True, new_version, link

        # elif new_version != self._current_version:
        # 	self._update_ready = False
        # 	self._update_version = new_version
        # 	self._update_link = link
        # 	self.save_updater_json()
        # 	return (True, new_version, link)

        # if no update, set ready to False from None
        self._update_ready = False
        self._update_version = None
        self._update_link = None
        return False, None, None

    def set_tag(self, name):
        """Assign the tag name and url to update to"""
        tg = None
        for tag in self._tags:
            if name == tag["name"]:
                tg = tag
                break
        if tg:
            new_version = self.version_tuple_from_text(self.tag_latest)
            self._update_version = new_version
            self._update_link = self.select_link(tg)
        elif self._include_branches and name in self._include_branch_list:
            # scenario if reverting to a specific branch name instead of tag
            tg = name
            link = self.form_branch_url(tg)
            self._update_version = name  # this will break things
            self._update_link = link
        if not tg:
            raise ValueError("Version tag not found: " + name)

    def run_update(self, force=False, revert_tag=None, clean=False, callback=None):
        """Runs an installation, update, or reversion of an addon from online source

        Arguments:
            force: Install assigned link, even if self.update_ready is False
            revert_tag: Version to install, if none uses detected update link
            clean: not used, but in future could use to totally refresh addon
            callback: used to run function on update completion
        """
        self._json["update_ready"] = False
        self._json["ignore"] = False  # clear ignore flag
        self._json["version_text"] = {}

        if revert_tag is not None:
            self.set_tag(revert_tag)
            self._update_ready = True

        # clear the errors if any
        self._error = None
        self._error_msg = None

        if self._verbose:
            print("Running update")

        if self._fake_install is True:
            # change to True, to trigger the reload/"update installed" handler
            if self._verbose:
                print("fake_install=True")
                print("Just reloading and running any handler triggers")
            self._json["just_updated"] = True
            self.save_updater_json()
            if self._backup_current is True:
                self.create_backup()
            self.reload_addon()
            self._update_ready = False

        elif force is False:
            if self._update_ready is not True:
                if self._verbose:
                    print("Update stopped, new version not ready")
                if callback:
                    callback(
                        self._addon_package, "Update stopped, new version not ready"
                    )
                return "Update stopped, new version not ready"
            elif self._update_link is None:
                # this shouldn't happen if update is ready
                if self._verbose:
                    print("Update stopped, update link unavailable")
                if callback:
                    callback(
                        self._addon_package, "Update stopped, update link unavailable"
                    )
                return "Update stopped, update link unavailable"

            if self._verbose and revert_tag is None:
                print("Staging update")
            elif self._verbose:
                print("Staging install")

            res = self.stage_repository(self._update_link)
            if res is not True:
                print("Error in staging repository: " + str(res))
                if callback is not None:
                    callback(self._addon_package, self._error_msg)
                return self._error_msg
            res = self.unpack_staged_zip(clean)
            if res < 0:
                if callback:
                    callback(self._addon_package, self._error_msg)
                return res

        else:
            if self._update_link is None:
                if self._verbose:
                    print("Update stopped, could not get link")
                return "Update stopped, could not get link"
            if self._verbose:
                print("Forcing update")

            res = self.stage_repository(self._update_link)
            if res is not True:
                print("Error in staging repository: " + str(res))
                if callback:
                    callback(self._addon_package, self._error_msg)
                return self._error_msg
            res = self.unpack_staged_zip(clean)
            if res < 0:
                return res
            # would need to compare against other versions held in tags

        # run the front-end's callback if provided
        if callback:
            callback(self._addon_package)

        # return something meaningful, 0 means it worked
        return 0

    def past_interval_timestamp(self):
        if self._check_interval_enable is False:
            return True  # ie this exact feature is disabled

        if "last_check" not in self._json or self._json["last_check"] == "":
            return True
        else:
            now = datetime.now()
            last_check = datetime.strptime(
                self._json["last_check"], "%Y-%m-%d %H:%M:%S.%f"
            )
            offset = timedelta(
                days=self._check_interval_days + 30 * self._check_interval_months,
                hours=self._check_interval_hours,
                minutes=self._check_interval_minutes,
            )

            delta = (now - offset) - last_check
            if delta.total_seconds() > 0:
                if self._verbose:
                    print("{} Updater: Time to check for updates!".format(self._addon))
                return True
            else:
                if self._verbose:
                    print(
                        "{} Updater: Determined it's not yet time to check for updates".format(
                            self._addon
                        )
                    )
                return False

    def get_json_path(self):
        """Returns the full path to the JSON state file used by this updater.

        Will also rename old file paths to addon-specific path if found
        """
        json_path = os.path.join(
            self._updater_path, "{}_updater_status.json".format(self._addon_package)
        )
        old_json_path = os.path.join(self._updater_path, "updater_status.json")

        # rename old file if it exists
        try:
            os.rename(old_json_path, json_path)
        except FileNotFoundError:
            pass
        except Exception as err:
            print("Other OS error occurred while trying to rename old JSON")
            print(err)
        return json_path

    def set_updater_json(self):
        """Load or initialize JSON dictionary data for updater state"""
        if self._updater_path is None:
            raise ValueError("updater_path is not defined")
        elif os.path.isdir(self._updater_path) is False:
            os.makedirs(self._updater_path)

        jpath = self.get_json_path()
        if os.path.isfile(jpath):
            with open(jpath) as data_file:
                self._json = json.load(data_file)
                if self._verbose:
                    print(
                        "{} Updater: Read in JSON settings from file".format(
                            self._addon
                        )
                    )
        else:
            # set data structure
            self._json = {
                "last_check": "",
                "backup_date": "",
                "update_ready": False,
                "ignore": False,
                "just_restored": False,
                "just_updated": False,
                "version_text": {},
            }
            self.save_updater_json()

    def save_updater_json(self):
        # first save the state
        if self._update_ready is True:
            if isinstance(self.update_version, tuple):
                self._json["update_ready"] = True
                self._json["version_text"]["link"] = self._update_link
                self._json["version_text"]["version"] = self._update_version
            else:
                self._json["update_ready"] = False
                self._json["version_text"] = {}
        else:
            self._json["update_ready"] = False
            self._json["version_text"] = {}

        jpath = self.get_json_path()
        outf = open(jpath, "w")
        data_out = json.dumps(self._json, indent=4)
        outf.write(data_out)
        outf.close()
        if self._verbose:
            print(
                self._addon
                + ": Wrote out updater JSON settings to file, with the contents:"
            )
            print(self._json)

    def json_reset_postupdate(self):
        self._json["just_updated"] = False
        self._json["update_ready"] = False
        self._json["version_text"] = {}
        self.save_updater_json()

    def json_reset_restore(self):
        self._json["just_restored"] = False
        self._json["update_ready"] = False
        self._json["version_text"] = {}
        self.save_updater_json()
        self._update_ready = None  # reset so you could check update again

    def ignore_update(self):
        self._json["ignore"] = True
        self.save_updater_json()

    # -------------------------------------------------------------------------
    # ASYNC stuff
    # -------------------------------------------------------------------------

    def start_async_check_update(self, now=False, callback=None):
        """Start a background thread which will check for updates"""
        if self._async_checking is True:
            return
        if self._verbose:
            print("{} updater: Starting background checking thread".format(self._addon))
        check_thread = threading.Thread(
            target=self.async_check_update,
            args=(
                now,
                callback,
            ),
        )
        check_thread.daemon = True
        self._check_thread = check_thread
        check_thread.start()

    def async_check_update(self, now, callback=None):
        """Perform update check, run as target of background thread"""
        self._async_checking = True
        if self._verbose:
            print(
                "{} BG thread: Checking for update now in background".format(
                    self._addon
                )
            )

        try:
            self.check_for_update(now=now)
        except Exception as exception:
            print("Checking for update error:")
            print(exception)
            if not self._error:
                self._update_ready = False
                self._update_version = None
                self._update_link = None
                self._error = "Error occurred"
                self._error_msg = "Encountered an error while checking for updates"

        self._async_checking = False
        self._check_thread = None

        if self._verbose:
            print(
                "{} BG thread: Finished checking for update, doing callback".format(
                    self._addon
                )
            )
        if callback:
            callback(self._update_ready)

    def stop_async_check_update(self):
        """Method to give impression of stopping check for update.

        Currently, does nothing but allows user to retry/stop blocking UI from
        hitting a refresh button. This does not actually stop the thread, as it
        will complete after the connection timeout regardless. If the thread
        does complete with a successful response, this will be still displayed
        on next UI refresh (ie no update, or update available).
        """
        if self._check_thread is not None:
            if self._verbose:
                print("Thread will end in normal course.")
            # however, "There is no direct kill method on a thread object."
            # better to let it run its course
            # self._check_thread.stop()
        self._async_checking = False
        self._error = None
        self._error_msg = None


# -----------------------------------------------------------------------------
# Updater Engines
# -----------------------------------------------------------------------------


class BitbucketEngine(object):
    """Integration to Bitbucket API for git-formatted repositories"""

    def __init__(self):
        self.api_url = "https://api.bitbucket.org"
        self.token = None
        self.name = "bitbucket"

    def form_repo_url(self, updater):
        return self.api_url + "/2.0/repositories/" + updater.user + "/" + updater.repo

    def form_tags_url(self, updater):
        return self.form_repo_url(updater) + "/refs/tags?sort=-name"

    def form_branch_url(self, branch, updater):
        return self.get_zip_url(branch, updater)

    def get_zip_url(self, name, updater):
        return "https://bitbucket.org/{user}/{repo}/get/{name}.zip".format(
            user=updater.user, repo=updater.repo, name=name
        )

    def parse_tags(self, response, updater):
        if response is None:
            return []
        return [
            {"name": tag["name"], "zipball_url": self.get_zip_url(tag["name"], updater)}
            for tag in response["values"]
        ]


class GithubEngine(object):
    """Integration to GitHub API"""

    def __init__(self):
        self.api_url = "https://api.github.com"
        self.token = None
        self.name = "github"

    def form_repo_url(self, updater):
        return "{}{}{}{}{}".format(
            self.api_url, "/repos/", updater.user, "/", updater.repo
        )

    def form_tags_url(self, updater):
        if updater.use_releases:
            return "{}{}".format(self.form_repo_url(updater), "/releases")
        else:
            return "{}{}".format(self.form_repo_url(updater), "/tags")

    def form_branch_list_url(self, updater):
        return "{}{}".format(self.form_repo_url(updater), "/branches")

    def form_branch_url(self, branch, updater):
        return "{}{}{}".format(self.form_repo_url(updater), "/zipball/", branch)

    def parse_tags(self, response, _):
        if response is None:
            return []
        return response


class GitlabEngine(object):
    """Integration to GitLab API"""

    def __init__(self):
        self.api_url = "https://gitlab.com"
        self.token = None
        self.name = "gitlab"

    def form_repo_url(self, updater):
        return "{}{}{}".format(self.api_url, "/api/v4/projects/", updater.repo)

    def form_tags_url(self, updater):
        return "{}{}".format(self.form_repo_url(updater), "/repository/tags")

    def form_branch_list_url(self, updater):
        # does not validate branch name.
        return "{}{}".format(
            self.form_repo_url(updater),
            "/repository/branches")

    def form_branch_url(self, branch, updater):
        # Could clash with tag names and if it does, it will
        # download TAG zip instead of branch zip to get
        # direct path, would need.
        return "{}{}{}".format(
            self.form_repo_url(updater),
            "/repository/archive.zip?sha=",
            branch)

    def get_zip_url(self, sha, updater):
        return "{base}/repository/archive.zip?sha={sha}".format(
            base=self.form_repo_url(updater),
            sha=sha)

    # def get_commit_zip(self, id, updater):
    # 	return self.form_repo_url(updater)+"/repository/archive.zip?sha:"+id

    def parse_tags(self, response, updater):
        if response is None:
            return []
        return [{
            "name": tag["name"],
            "zipball_url": self.get_zip_url(tag["commit"]["id"], updater)
        } for tag in response]


# -----------------------------------------------------------------------------
# The module-shared class instance,
# should be what's imported to other files
# -----------------------------------------------------------------------------

Updater = SingletonUpdater()
